Previously on "Supergirl" Season 2 episode 2, Cat Grant left CATCO and said goodbye to Kara Danvers (Melissa Benoist). Clark Kent (Tyler Hoechlin) also said goodbye to his cousin as he needs to go back to Daily Planet.
"Supergirl" Season 2 Episode 2 kicks-off with the cousins, Supergirl and Superman doing heroic deeds in National City. Clark Kent has decided to spend a bit more time with Kara and help out at the D.E.O. with their missions. The following scenes inside the D.E.O. show that there are still signs of disagreement between the Martian Manhunter and Superman regarding the D.E.O. keeping kryptonite in stock as a precaution to Kyptonian threat.
Meanwhile at Cadmus, Michael Corbin has been revived, and a mysterious female doctor reveals that he has been modified as an android that is powered with Kryptonite. Back at the D.E.O., Hank Henshaw reprimands Supergirl for not following protocol in the capture of an alien threat. Suddenly, the D.E.O. experienced another energy drain that comes from the holding area where the new male Kryptonian is kept. The stress between Superman and Henshaw is even more evident here.
Kara goes back to work with Clark at CATCO, and Cat Grant then introduces her to her new boss, Snapper Carr, who seems to show little to no interest in his new stringer. Much to Kara's disappointment, Carr did not approve of her to join his team, but was resolved by the end of the episode. It is also later revealed that Cat will be leaving CATCO, with Jimmy Olsen taking over while she is gone.
Clark meets up with Kara at her place and tells her that he needs to go back to Metropolis. They end up going against Metallo, which resulted in their loss and Kara getting hurt. There is a scene here that pay homage to the "Crisis on Infinite Earths" cover art, according to Screen Rant. The two managed to escape and regroup back at the D.E.O. where they learn that a shipment of Kryptonite went missing a few months ago, and that there may be a mole working for Cadmus within the D.E.O.. In a hacked broadcast, Cadmus then announces its presence to the world.
Another Metallo was created, and the two Metallos begin to simultaneously attack Metropolis and National City, which resulted in significant casualties. Supergirl then suggested that they team up with Hank and Alex to defeat the two Metallos. With the two Metallos defeated, Hank finally agrees to have Superman dispose of the D.E.O.'s remaining Kryptonite, and Clark Kent returns to Metropolis.
